Cellulosic composition of matter containing tripropionin



5. J. CARROLL,

Oct. 6, 1931.

CELLULOSIC COMPOSITION OF MATTER CONTAINING TRIPROPI ONIN Filed Aug. 30, 1929 m m y w w w N A\//. D. Tc m m m m m. m

% PLHSTICIZER gwwml ov EFLQWELTL J Ear: EJ'L'L Patented Oct. 6, 1931 UNITED \STATES PATENT OFFICE STEWART J. CARROLL, OF NEW YORK, ASSIGNOR TO EASTMAN KODAK COMPANY, 01! ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK GELL'ULOSIC COMPOSITION OF MATTER CONTAINING TRIPROPIONIN Application filed August 80, 1929. Serial No. 889,459.

This invention relates to compositions of matter in which'cellulose derivatives, such as cellulose acetate, cellulose nitrate orcellulose ether, are combined or mixed with other substances, such as a compatible plasticizer, and a common solvent for both, with or without other useful addition agents, so that the resulting roduct will have properties such as will ma e the composition highly advantageous for use in the plastic and analogous arts, such, for instance, as the manufacture of wrapping sheets, photographic film, artificial silk, varnishes or lacquers, and the-like.

One object of this invention is to produce a composition of matter which may be made into permanently transparent, strong and flexible sheets or films of deslred thinness which are substantially waterproof, are unaffected by ordinary photographic fluids and possess the desired properties of a support or sensitive photographic coatings. Another object of my invention is to produce a composition which is capable of easy and convenient manipulation in the plastic. and analogous arts, such as in the manufacture of sheets, films, artificial silk filaments, varnishes, lacquers and the like; -and to produce a composition which will not injure, or

of these and other addition agents are-also added for the purpose of reducing the inflammability of the product. Plastic inducing agents, such as the higher alcohols and their esters, are sometimes also added. Similarly addition compounds of various kinds have been employed to increase flexibility, transparency, toughness and other properties which will enhance the value of the relasticizing or con 'tioning agents as.

sulting product. Addition products for the same or similar purposes are also added to cellulose acetates, nitrates and ethers to prepare them for use in the other plastic arts, such as in the manufacture of lacquers, varnishes, artificial silk filaments, moulded compounds and the like. While the plasticizers or other addition agents heretofore discovered have had, their utility in the art, the increasing use to which cellulose derivatives have been put and the increasing number of desirable properties required of the cellulose derivative for most purposes has made the discovery of new and economical plasticizers or other addition agents a matter of 5 considerable importance to the art.

I have discovered that valuable properties may be induced in and/ or contributed to compositions containing cellulose derivatives,'such as cellulose acetate, by adding thereto the 7 plasticizing compound tripropioninfin the presence of a solvent, such as acetone, which will dissolve both the cellulose derivative and plasticizer. This plasticizer is a liquid at ordinary atmospheric temperature and has the structural formula of It is compatible with cellulose derivatives and particularly compatible with cellulose acetate in the percentages hereinafter given. It is not an expensive compound and not 7 particularly diflicult to produce, or obtain upon the open market. The particularly useful properties which it induces in or contributes to a cellulosic composition containing 96 it are hereinafter enumerated.

In order that those skilled in this art may better understand my invention I would state, by way of illustration, that for the manufacture of photographic film or other sheets my new composition of matter may be compounded as follows: 100 parts of'acetone soluble cellulose acetate i. e. cellulose acetate containing from 36% to 42% acetyl radical, approximately, is dissolved with stirring at atmospheric temperature in 300 to 400 parts, preferably 400 parts, by Weight, of" acetone. To this solution may be added from 10 to 50 parts by weight, of tripropionin, it being found preferable to employ approximately 50 parts thereof. Within the limits stated, the amount of plasticizer may be decreased or increased, depending upon whether it is desired to decrease or increase, respectively, the properties which this plasticizer contributes to the finished product. The amount of solvent employed may also be decreased or increased, depending upon whether it is desired to have a more or less freely flowing composition, respectively.

A composition of matter prepared as above described may be deposited upon any suitable film forming surface to form a' film or sheet, as is well known to those skilled in the art. A film so produced has permanently brilliant transparency and low inflammability, burnin no more readily than ordinary newsprint, uch film is exceptionally tough and flexible as shown by the fact that it will withstand many folds upon a modified Schopper fold-tester (commonly used for such purposes) without breaking and that even after being subjected for 58 days to air maintained at a temperature of C. the film still maintains flexibility, demonstrating that the film will withstand ordinary usage satisfactorily for many years, whereas a film formed from a mere solution of cellulose acetate in acetone or other similar solventis brittle and fragile after being subjected to thesame treatment for as little as thirty days or even a lesser time. above advantageous properties of a product produced from my new com osition is considerably in excess of that 0 products produced with what have previously been regarded as the better plasticizers.

Other similar solvents (instead of acetone) which are compatible with the cellulose acetate and my new plasticizer may also occur to those skilled in this art. In like manner this plasticizer may be compounded with other single organic esters of cellulose, such as cellulose propionate, butyrate and the like, or with mixed organic and/or inorganic esters, such as cellulose aceto-stearate, acetomalate, or cellulose nitro-acetate, or with the cellulose ethers, a suitable solvent which will dissove both the cellulosic derivative and the plasticizer being employed.

The accompanying drawing, forming a part of this application, clearly illustrates the particular advantages of employing my novel plasticizer in the plastic arts. In this drawing there are plotted lines or curves graphi- The sum total of the,

cally depicting the properties of film produced' from a composition containing cellulose acetate and this plasticizer. On the horizontal axis is indicated the various percentages of my plasticizer that maybe employed with the ce llulosic derivative, this percentage being given in parts added to the cellulose derivative rather than parts of the composition; for instance, 30 parts plasticizer added to 100 parts cellulose-acetate is denoted as 30% plasticizer added. On the vertical axis at (a), on the left, is indicated in percentage over the check sample the initial flexibility of a film which hasbeen formed as described from my novel composition and which has been subjected to air at 50 C. for 24 hours to free it of solvent; the rate of combustion of that film is also indicated by this same column (a) at (b) on the right is indicated the the length of time in days that the film will maintain flexibility when subjected to air kept at a temperature of 65 C. The curve (A) depicts initial flexibility of the film, the curve (B) depicts the ability of the film to maintam flexibility and the curve (C) depicts the rate of combustion of the film all with various percentages of my novel plasticizer and all as compared to the respective properties of a film produced from a solution of cellulose acetate in acetone and a hypothetical inert material substituted for the plasticizer as denoted by curve (D) indicating unity of 100% and 30 days for (a) and (b). It will thus be noted that my novel plasticizer has the faculty of giving, to a product produced therefrom, exceptionally good initial flexibility and a low combustion rate, and that the product maintains its flexibility quitewell. The preferred percentage of my plastlclzer which it is desirable to employ to contribute any particular property to the final product will be obvious from an inspection of this drawing; the best percentage to employ Wlll depend upon which roperty it is desired to feature most in the nal product. In as much as my above described composition of matter is quite useful in the production of films and sheets it will be apparent that my new plasticizer may also be employed with advantage in the other branches of the plastic art. For instance, my above described composition of matter may be employed in the manufacture of artificial silk by the dry spinning method. With the proper coagulating bath it may also be employed for wet spinning. It may be desired to employ a composition of difierent viscosity or evaporation characteristics but this is a mere matter changing the solvent proportion or adding evaporation retardants such as triacetin or other high or intermediate boiling constituents, as has been well known in the art for more than a decade. My novel plasticizer may also be employed with advantage in connection with a number of the known lacquer and varnish formulae with which it may be found to be compatible. In such cases the plasticizer is usually first put into solution with the cellulose derivative solution and if non-solvents are added for the purpose of cheapening the composition they are added only to such an extent as will not recipitate the derivative from' solution. ther uses within the scope of my invention will also suggest themselves to those skilled in the art.

What I claim as my invention, and desire v to be secured by Letters Patent of the United States, is:

1. A composition of matter comprising a cellulose derivative and tripropionin.

2. A composition of matter comprising cellulose acetate and tripropionin. v

3. A composition of matter comprising parts cellulose acetate and from about 10 to 50 parts, by weight, of tripropionin.

4. .A composition of matter comprising 100 parts of cellulose acetate and approximately 50 arts, by weight, of tripropionin.

igned at Rochester, New York, this 27th day of August, 1929.

- STEWART J. CARROLL. 

